private void InterstitialAd_AdReceived(object sender, System.EventArgs e)
        {
            Device.BeginInvokeOnMainThread(() => this.interstitialAd.PresentFromRootViewController(UIApplication.SharedApplication.Windows[0].RootViewController));

            AdReceived?.Invoke(null, null);
        }
        public override void OnAdClosed()
        {
            UnMmuteSound();

            AdReceived?.Invoke(this, EventArgs.Empty);
        }